Answer
The formed elements of the blood that are cell fragments are platelets.
Work Step by Step
There are three different formed elements which are red blood cells (RBCs (erythrocytes)), white blood cells (WBCs (leukocytes)), and finally platelets. The reason why platelets are identified as cell fragments is that they have no nucleus. In other words, they aren't in the form of a normal, full cell, but rather in the form of fragments. Both red and white blood cells have a nucleus so they wouldn't be identified as fragments.
